Except for the introduction of electrical or mechanical devices, shaving methods have changed little over the centuries, the traditional wet shave still being predominant. Attempts are made to soften the hair by the application of wetted soap lathers, foams, gels or oils of various natures to make the hair somewhat easier to cut. These pre-shaving applications do little if anything to alleviate the problems encountered when shaving, specifically, razor bumps (pseudo folliculitis barbae), razor burn (microscopic cuts that easily become infected or inflamed), nicking or more serious cutting of the skin, and premature wear on the cutting edge of the blade being used. The applications mentioned above (soap lathers, gels, etc) usually require the use of additional ‘after-shave’ products of one form or another to calm or condition the skin after shaving.
U.S. Pat. No. 4,608,392 describes the use of polyether oligomers in a skin care product.
U.S. Pat. No. 6,264,963 describes a skin care composition whose benefits are achieved by using petrolatum or mineral oil. Although this patent mentions “softening of the hair prior to cutting” it makes no claim or suggestion that their formula could be used for shaving.
U.S. Pat. No. 4,784,849 and corresponding Canadian Patent 1,244,350 describe skin care and shaving compositions comprising phospholipids.
U.S. Pat. No. 5,345,680 describes a shaving aid for wet razor comprising polymers.
U.S. Pat. No. 5,902,574 describes a shaving preparation that uses cysteamine.
British Patent 429,786 describes a shaving preparation comprising sulphonated oils.
British Patent 454,658 describes a shaving cream, however, there is no mention of the use of either glycerin or diglycerin.